So there had been a lot of discussion about "Herp I want a pyrat guild lulz0r" and the sort, But what I want to discuss is different paths or roads if you will, within each guild. Allow me to elaborate. Going on the assumption there will be the Synod and CoW - if you were to join the CoW they could offer you the path of becoming an experimental necromancer, or if you joined the Synod they could offer you a different path within the guild that allowed you to take on a more specialised role.
Obviously these options wouldn't be open to you as soon as you joined the guild, some might be offered soon after joining, halfway through, or near the end.
Instead of the same story line for each guild, maybe 2 -3 different paths you could take within each guild, going into a specialty area or something to that effect.
Something to think about . My 2 cents.